Field of the Invention
The present invention relates to an X-ray generation apparatus and an X-ray imaging apparatus.
Description of the Related Art
The enlargement ratio of an X-ray fluoroscopic image can increase as the distance between an object and a target that is an X-ray generation unit is short. There is known an X-ray generation apparatus in which to obtain a sufficient enlargement ratio even in a case in which the object is located at a deep position, a projecting portion which is long projecting from the main body portion of a storage container is provided on the main body portion, and an X-ray generation unit is attached to the distal end of -the projecting portion. Such an X-ray generation apparatus is described in Japanese Patent Laid-Open No. 2018-73625.
In the X-ray generation apparatus as described above, a large potential difference is generated between the storage container and the cathode of the X-ray generation tube, and the storage container includes a bending portion formed at the connecting portion between the main body portion and the projecting portion. For this reason, discharge readily occurs between the bending portion of the storage container and the cathode of the X-ray generation tube. To solve this problem, Japanese Patent Laid-Open No. 2018-73625 describes arranging the bending portion between the cathode and the anode in the tube axis direction of the X-ray generation tube and making the distance between the bending portion and the cathode longer than the distance between the anode and the cathode. In addition, Japanese Patent Laid-Open No. 2018-73625 describes that when making the distance between the bending portion and the cathode shorter than the distance between the anode and the cathode, the bending portion is arranged between the cathode and the anode in the tube axis direction, and an insulating member is arranged so that the bending portion is not directly viewed from the cathode.
In both of the two approaches described in Japanese Patent Laid-Open No. 2018-73625, to reduce discharge between the bending portion of the storage container and the cathode of the X-ray generation tube, it is necessary to arrange the bending portion of the storage container between the anode-insulating tube joint portion (the joint portion between the anode and the insulating tube, outside the X-ray generation tube (on the oil side)) and the cathode-insulating tube joint portion (the joint portion between the cathode and the insulating tube, outside the X-ray generation tube (on the oil side)) in the tube axis direction. However, to improve the enlargement ratio when capturing an object arranged at a deeper position, the length of the projecting portion of the storage container is required to be increased. Japanese Patent Laid-Open No. 2018-73625 does not provide a solution to the requirement.
The present inventor found that the longer the distance between the bending portion and the cathode becomes in the structure in which the cathode is arranged, between the anode and the bending portion of the storage container, in the tube axis direction, the more unstable the operation of the X-ray generation apparatus becomes.